Bleaching compositions are used in the home and in industrial applications for bleaching stains on hard surfaces and soiled fabrics. Hypochlorite bleaches are effective at removing stains, when used in relatively high concentrations, but hypochlorite, along with other active chlorine bleaches, cause rather severe damage to fabric colors as well as causing damage to the textile fibers. Additionally, hypochlorite liquid bleaches present handling and packaging problems. Color and fabric damage can be minimized by using milder oxygen bleaches such as sodium perborate or potassium monopersulfate. The stain removal characteristics of these peroxygen bleaches, however, are much less desirable than those of the harsher halogen bleaching agents. As a result, commercial bleaching compositions which contain peroxygen bleaches commonly utilize activators, i.e., compounds that enhance the performance of the peroxygen bleach. Bleaching compositions employing different types of bleach activators have been disclosed, for example, in: Poplin, U.S. Pat. No. 1,940,768, Dec. 26, 1933; Baevsky, U.S. Pat. No. 3,061,550, Oct. 30, 1962; MacKellar et al., U.S. Pat. No. 3,338,839, Aug. 29, 1967; and Woods, U.S. Pat. No. 3,556,711, Jan. 19, 1971.
The continuing attempt to find effective activators, other than those already present and employed in the art, include U.S. Pat. No. 3,822,114 which teaches a bleaching composition comprising a peroxygen bleaching compound and a ketone or aldehyde bleaching activator. U.S. Pat. No. 3,822,114 fails to provide an effective and user acceptable bleaching composition as the bleaching process cannot be carried out at room temperature requiring instead that the washing to remove fabric stains be carried out at temperatures in excess of 100.degree. F.
Robert W. Murray in his article entitled "Dioxiranes," Chem Rev., 1989, 1187-1201 describes the formation of dioxiranes from ketones and monopersulfates but fails to teach the ketal cycloalkanedione bleach activators disclosed in copending application Ser. No. 7/870,362 or the bicyclic or tricyclic diketone activators of the instant invention, which make possible the carrying out of room temperature bleaching of stained fabrics and hard surfaces.
Waldemar Adam et al., in Acc. Chem. Res. 1989, 22,205-211 teaches the formation of dioxiranes from monopersulfates and ketones but as in the case of Murray, the publication fails to disclose the criticality of the selection of the bleach activator if satisfactory bleaching results at room temperature are to be realized.
In copending patent application Ser. No. 7/870,362 assigned to the same assignee as the instant application, bleach activators representing an improvement over these previously disclosed for use in the cleaning of fabrics and hard surfaces are disclosed. The disclosed activators are capable of activating the peroxygen compound at room temperature while causing less damage to the fabric being cleaned. The bleach activators described in the aforesaid application are ketal cyclohexanediones and when admixed with the peroxygen compound allow the user to effectively remove stains and soil from fabrics and/or hard surfaces at room temperature.
It is an object of this invention to provide improved bleaching compositions for use in the room temperature bleaching and/or removal of stains from fabrics and hard surfaces.
It is a further object of the invention to provide new and enhanced activating agents for peroxygen bleaches.
It is still another object of the invention to provide improved concentrated, bleaching compositions for use alone or in combination with other conventional laundering adjuvants for enhanced removal of stains on fabrics or hard surfaces.
It has now been found that by combining a peroxygen bleaching agent with a bicyclic or tricyclic ketone as activator for the bleaching agent, improved compositions are obtained which accomplish the foregoing objects and are unexpectedly superior in their bleaching effectiveness to the compositions of the prior art.
The peroxygen bleaching compositions of the invention can be used directly in aqueous solution to bleach a fabric or a hard surface or in the alternative the bleaching compositions can be incorporated as an additive to a cleaning composition such as a powdered laundry detergent, a non aqueous laundry detergent, a scouring powder, a hard surface cleaning composition, a powdered automatic dishwashing composition, a nonaqueous automatic dishwashing composition, a hair bleaching composition, a wound cleansing composition, a dental cleansing composition, a paper bleaching composition, a prespotter and the like.